GM S-Series Pick-ups and SUV's 1994-1999 Repair Guide

Headlights

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REMOVAL & INSTALLATION



Sealed Beam

See Figure 1



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Fig. Fig. 1: Exploded view of a common sealed beam headlight mounting (with separate headlight bezel shown)

If some or all of the headlight bulbs being replaced still operate, refer to the headlight aiming procedure later in this section to ease checking or adjustment of the headlights after installation.

1994-95 MODELS

See Figures 2, 3 and 4



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Fig. Fig. 2: Loosen the retaining ring fasteners ...



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Fig. Fig. 3: ... then remove the retaining ring



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Fig. Fig. 4: Slide the headlamp forward and disengage the electrical connection

  1. If necessary, remove the grille from the vehicle. Refer to Body & Trim of this repair guide for the proper procedure.
  2.  
  3. Unfasten the headlamp retaining ring fasteners, then remove the ring.
  4.  
  5. Grasp the headlamp and rotate it to the right and remove the headlamp.
  6.  
  7. Unplug the electrical connection from the rear of the lamp.
  8.  

To install:
  1. Attach the electrical connection to the rear of the headlamp.
  2.  
  3. Install the headlamp in the vehicle.
  4.  
  5. Install the retaining ring and tighten the retaining fasteners.
  6.  
  7. If removed, install the grille. Refer to Body & Trim of this repair guide for the proper procedure.
  8.  

1996-97 MODELS
  1. Unfasten the headlamp retaining ring fasteners, then remove the ring.
  2.  
  3. Remove the headlamp.
  4.  
  5. Unplug the electrical connection from the rear of the lamp.
  6.  

To install:
  1. Attach the electrical connection to the rear of the headlamp.
  2.  
  3. Install the headlamp in the vehicle.
  4.  
  5. Install the retaining ring and tighten the retaining fasteners.
  6.  

Composite Beam

Some vehicles covered by this information were equipped with composite headlight assemblies. The composite headlight assembly houses the headlamp and side marker lamp bulbs. In most cases, the assembly is bolted in a fixed position so no adjustment is necessary or possible. Also, due to space constraints, no access may be provided to withdraw the bulbs, so the replacement usually requires removal of the composite assembly.

The composite headlight assemblies use Halogen bulbs which contain a gas under pressure. Handling a bulb improperly could cause it to shatter into flying glass fragments. To help avoid personal injury follow the precautions closely.

Whenever handling Halogen bulb ALWAYS follow these precautions:



Do not directly touch the glass of the bulb. The oil from your skin can cause the bulb to explode when it is turned on.
 
Turn the lamp switch OFF and allow the bulb to cool before changing it. Leave the switch OFF until the change is complete.
 
ALWAYS wear eye protection when changing a Halogen bulb.
 
DO NOT drop or scratch the bulb. Keep moisture away.
 
Place the used bulb in the new bulb's carton and dispose of it properly.
 

1994-95 MODELS

See Figure 5

  1. Disconnect the negative battery cable.
  2.  
  3. If replacing the right side bulb, remove the battery from the vehicle.
  4.  
  5. If replacing the left side bulb, remove the intake air box.
  6.  
  7. Remove the grille from the front of the vehicle.
  8.  
  9. Remove the retaining screw from the engine side of the radiator support, then remove the headlight capsule-to-radiator support screws.
  10.  
  11. Pull the composite headlight assembly forward slightly, then unplug the headlamp and side marker lamp wiring connectors.
  12.  
  13. Remove the headlight assembly from the vehicle. Remove the necessary bulb(s) from the assembly.
  14.  



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Fig. Fig. 5: Composite headlight assembly mounting

To install:
  1. Install new bulbs, as necessary to the composite headlight assembly.
  2.  
  3. Position the assembly to the vehicle and attach the connectors.
  4.  
  5. Install the assembly retaining screws and tighten to 62 inch lbs. (7 Nm).
  6.  
  7. Install the grille to the front of the vehicle.
  8.  
  9. Install the air intake box and/or battery, as applicable.
  10.  
  11. Connect the negative battery cable and verify proper lamp operation.
  12.  

1997-99 MODELS NOT RETAINED BY A LOCKING TAB

See Figure 6 and 7



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Fig. Fig. 6: Some composite headlight assembly retainers are located under the hood



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Fig. Fig. 7: These retainers can be removed by grasping the retainers and pulling them up until the pin is located at the largest part of the hole, then remove the retainers while supporting the lens assembly

  1. Disconnect the negative battery cable.
  2.  
  3. On 1996-97 models remove the lens assembly as follows:
    1. If equipped, remove the plastic caps that cover the headlight retaining pins or screws, then remove the pins or screws while supporting the lens assembly.
    2.  

  4.  
  5. On 1998-99 models remove the lens assembly as follows:
    1. Open the hood and locate the headlight retainers (usually two). The headlight retainers are plastic or metal strips with an elongated hole in it. Grasp the retainers and pull them up until the pin is located at the largest part of the hole and remove the retainers while supporting the lens assembly.
    2.  

  6.  
  7. Unplug the bulb electrical connection(s). Remove the bulb from the headlight by pushing them in and turning the 1 / 4 turn counterclockwise.
  8.  

To install:
  1. Install the bulbs in the headlight assembly by pushing in rotating it 1 / 4 turn clockwise.
  2.  
  3. Attach the electrical connectors for the headlight and side marker assemblies.
  4.  
  5. On 1996-97 models install the lens assembly as follows:
    1. Place the lens in position, install the retaining pins or screws and tighten the pins or screws to 62 inch lbs. (7 Nm). If equipped, install the plastic caps.
    2.  

  6.  
  7. On 1998-99 models install the lens assembly as follows:
    1. Install the lens assembly, then place the largest hole of the retainer over the pin and push the retainer down until the pin is at the top of the elongated hole.
    2.  

  8.  
  9. Connect the negative battery cable and check for proper light operation.
  10.  

1997-99 MODELS RETAINED BY LOCKING TAB

See Figures 8 through 14



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Fig. Fig. 8: The headlamp assembly may use one or more locking tabs



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Fig. Fig. 9: Turn the locating tab until it releases, then pull forward to disconnect the lens assembly from the top retaining pin



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Fig. Fig. 10: Pull gently on the fender side of the lens to disconnect it from the second retaining pin ...



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Fig. Fig. 11: ... then slide the lens sideways to disconnect it from the third and last retaining pin



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Fig. Fig. 12: Tilt the lens forward to access the bulb assemblies



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Fig. Fig. 13: Unplug the halogen bulb electrical connector



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Fig. Fig. 14: Turn the bulb assembly to the left to remove it from the lens. Do not touch the bulb glass

  1. Disconnect the negative battery cable.
  2.  
  3. If necessary to access the locking tab, remove the grille assembly.
  4.  
  5. Turn the locking tab (usually red) upward to the unlocked position. The unlocked position should be marked on the back of the lens assembly.
  6.  
  7. Gently pull the top of the lens forward to disconnect it from the retainer.
  8.  
  9. Pull gently on the fender side of the lens to disconnect it from the second retaining pin, then slide the lens sideways to disconnect it from the third and last retaining pin
  10.  
  11. Unplug the bulb electrical connection(s). Remove the bulb from the headlight by pushing them in and turning the 1 / 4 turn counterclockwise.
  12.  

To install:
  1. Install the bulbs in the headlamp assembly by pushing in rotating it 1 / 4 turn clockwise.
  2.  
  3. Attach the electrical connectors.
  4.  

When connecting the lens assembly to the retainers, make sure the headlight electrical harness is being pinched.

  1. Connect the lens assembly to the lower retainers.
  2.  
  3. Align the top retainer with the hole in the lens assembly and gently push in on the top of the assembly until it is firmly seated on the retainer.
  4.  
  5. Push the locking tab downward until the tab is in the locked position
  6.  
  7. If removed for access, install the grille assembly.
  8.  
  9. Connect the negative battery cable and check for proper light operation.
  10.  

HEADLIGHT AIMING



See Figures 15 and 16

The headlights must be properly aimed to provide the best, safest road illumination. The lights should be checked for proper aim and adjusted as necessary. Certain state and local authorities have requirements for headlight aiming; these should be checked before adjustment is made. Headlight adjustment may be temporarily made using a wall, as described below, or on the rear of another vehicle. When adjusted, the lights should not glare in oncoming car or truck windshields, nor should they illuminate the passenger compartment of vehicles driving in front of you. These adjustments are rough and should always be fine-tuned by a repair shop which is equipped with headlight aiming tools. Improper adjustments may be both dangerous and illegal.

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Fig. Fig. 15: Headlight adjustment screw locations for most sealed beam headlight adjusting plates



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Fig. Fig. 16: The composite headlight adjustment screw can be accessed through a hole in the radiator support-1996 2.2L Hombre

For most S/T vehicles, horizontal and vertical aiming of each sealed beam unit is provided by two adjusting screws which move the retaining ring and adjusting plate against the tension of a coil spring. There is no adjustment for focus; this is done during headlight manufacturing.

Because the composite headlight assembly is bolted into position, no adjustment should be necessary or possible. Some applications however may be bolted to an adjuster plate or may be retained used adjusting screws. If so, follow this procedure when adjusting the lights, BUT always have the adjustment checked by a reputable shop.

Before removing the headlight bulb or disturbing the headlamp in any way, note the current settings in order to make adjusting the headlights upon reassembly easier. If the high or low beam setting of the old lamp still works, this can be done using the wall of a garage or a building:

  1. Park the truck on a level surface, with the fuel tank no more than 1 / 2 full and with the vehicle empty of all extra cargo (unless normally carried). The vehicle should be facing a wall which is no less the 6 feet (1.82 m) high and 12 feet (3.96 m) wide. The front of the vehicle should be about 25 feet (7.62 m) from the wall.
  2.  

The truck's fuel tank should be about half full when adjusting the headlights. Tires should be properly inflated, and if a heavy load is normally carried in the bed, it should remain there.

  1. If this is be performed outdoors, it is advisable to wait until dusk in order to properly see the headlight beams on the wall. If done in a garage, darken the area around the wall as much as possible by closing shades or hanging cloth over the windows.
  2.  
  3. Turn the headlights ON and mark the wall at the center of each light's low beam, then switch on the brights and mark the center of each light's high beam. A short length of masking tape which is visible from the front of the truck may be used. Although marking all 4 positions is advisable, marking 1 position from each light should be sufficient.
  4.  
  5. If neither beam on 1 side of the vehicle is working, park another like-sized truck in the exact spot where the truck was and mark the beams using the same side light on that truck. Then switch the trucks so the S/T is back in the original spot. The truck must be parked no closer to or farther away from the wall than the second vehicle.
  6.  
  7. Perform the necessary repairs, but make sure the truck is not moved or is returned to the exact spot from which the lights were marked. Turn the headlights ON and adjust the beams to match the marks on the wall.
  8.  
  9. Have the headlight adjustment checked as soon as possible by a reputable repair shop.
  10.  

 
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